Cryotherapy, sometimes known as cold therapy, is the local or general use of low temperatures in medical therapy. Cryotherapy may be used to treat a variety of tissue lesions. The most prominent use of the term refers to the surgical treatment, specifically known as cryosurgery or cryoablation. Cryosurgery is the application of extremely low temperatures to destroy abnormal or diseased tissue and is used most commonly to treat skin conditions.

Cryotherapy is used in an effort to relieve muscle pain, sprains and swelling after soft tissue damage or surgery. For decades, it has been commonly used to accelerate recovery in athletes after exercise. Cryotherapy decreases the temperature of tissue surface to minimize hypoxic cell death, edema accumulation, and muscle spasms, all of which ultimately alleviate discomfort and inflammation. It can be a range of treatments from the application of ice packs or immersion in ice baths (generally known as cold therapy), to the use of cold chambers.

While cryotherapy is widely used, there is little evidence as to its efficacy that has been replicated by or shown in large controlled studies. Its long-term side effects have also not been studied. However, it is important to note that a number of studies have shown a possible association between cryotherapy and adverse effects. The adverse events include the risk of frostbite, superficial nerve palsies, Raynaud’s phenomenon, cold urticaria and delayed regeneration. The potential harm of cryotherapy has raised doubts regarding its use and effectiveness which has led to guidance against the use of cryotherapy. However, there is a study that concludes that cryotherapy has a positive impact on the short-term recovery of athletes. Cryotherapy helped manage muscle soreness and facilitate recovery within the first 24 hours following a sport-related activity. Athletes who use cryotherapy within the first 24 hours to alleviate pain recovered at a faster rate than athletes who did not use cryotherapy after their sport-related activity.

Although there are many positive effects of cryotherapy in athletes' short-term recovery, in recent years, there has been much controversy regarding whether cryotherapy is actually beneficial or may be causing the opposite effect. While inflammation that occurs post-injury or from a damaging exercise may be detrimental to secondary tissue, it is beneficial for the structural and functional repair of the damaged tissue. Therefore, some researchers are now recommending that ice not be used so as not to delay the natural healing process following an injury. The original RICE (rest, ice, compression, elevation) method was rescinded because the inflammatory response is necessary for the healing process, and this practice may delay healing instead of facilitating it. Animal studies also show that a disrupted inflammatory stage of healing may lead to impaired tissue repair and redundant collagen synthesis.

Additionally, if performed regularly post-exercise, cryotherapy can have a negative effect on muscle mass, strength gains, and rate of muscle protein synthesis. This is due to the fact that cryotherapy blunts the chronic skeletal muscle adaptations from resistance training exercises. These harmful effects can be easily avoided by not using cryotherapy during an athlete's training season or pre-season phase.